TGeoVolume* gfoil1(Bool_t kap = kTRUE, TGeoManager *mgr)
{
	// load libraries
	gSystem->Load("libGeom");
	TGeoManager *mgr = new TGeoManager("test", "");
	
	// instantiate the media:
	// - vacuum for the container volume
	// - kapton for the pysical volumes
	TGeoMedium *vacuum = mgr->GetMedium("VACUUM");
	
	// conversion factor
	Double_t fgkmm = 0.1;
	
	// label
	char type[3];
	if (kap) strcpy(type, "KP"); else strcpy(type, "AL");
	
	// size of the virtual box containing exactly this volume
	Double_t length    = fgkmm * 243.18;
	Double_t width     = fgkmm *  15.95;
	Double_t thickness = fgkmm *   0.05;
	if (!kap) {
		length    -= fgkmm * 0.4;
		width     -= fgkmm * 0.4;
		thickness  = fgkmm * 0.02;
	}
	
	// define the length of all sectors (from leftmost to rightmost)
	Int_t i;
	Double_t sectorLength[] = { 140.71,  2.48,  26.78,  4.00,  10.00,  24.40,  10.00,  24.81 };
	for (i = 0; i < 8; i++) sectorLength[i] *= fgkmm;
	if (!kap) {
		sectorLength[0] -= fgkmm * 0.2;
		sectorLength[4] -= fgkmm * 0.2;
		sectorLength[5] += fgkmm * 0.4;
		sectorLength[6] -= fgkmm * 0.4;
	}
	
	// as shown in the drawing, we have three different widths in this shape:
	Double_t widthMax  = fgkmm * 15.95;
	Double_t widthMed1 = fgkmm * 15.00;
	Double_t widthMed2 = fgkmm * 11.00;
	Double_t widthMin  = fgkmm *  4.40;
	if (!kap) {
		widthMax  -= fgkmm * 0.4;
		widthMed1 -= fgkmm * 0.4;
		widthMed2 -= fgkmm * 0.4;
		widthMin  -= fgkmm * 0.4;
	}
	
	// the vertices of the polygon are arrays correctly ordered in the counterclockwise direction:
	// initially we place the point 0 in the origin, and all others will be defined accordingly
	Double_t x[14], y[14];
	x[ 0] = 0.0;
	y[ 0] = 0.0;
	
	x[ 1] = x[0] + length;
	y[ 1] = 0.0;
	
	x[ 2] = x[1];
	y[ 2] = -widthMin;
	
	x[ 3] = x[2] - sectorLength[7];
	y[ 3] = y[2];
	
	x[ 4] = x[3];
	y[ 4] = -widthMed1;
	
	x[ 5] = x[4] - sectorLength[6];
	y[ 5] = y[4];
	
	x[ 6] = x[5];
	y[ 6] = -widthMin;
	
	x[ 7] = x[6] - sectorLength[5];
	y[ 7] = y[6];
	
	x[ 8] = x[7];
	y[ 8] = -widthMed2;
	
	x[ 9] = x[8] - sectorLength[4];
	y[ 9] = y[8];
	
	x[10] = x[9] - sectorLength[3];
	y[10] = -widthMed1;
	 
	x[11] = x[10] - sectorLength[2];
	y[11] = y[10];
	
	x[12] = x[11] - sectorLength[1];
	y[12] = -widthMax;
	
	x[13] = x[0];
	y[13] = -widthMax;
	
	// then, we shift all points in such a way that the origin will be at the centers
	for (i = 0; i < 14; i++) {
		x[i] -= 0.5*length;
		y[i] += 0.5*width;
	}
	
	// create the shape
	TGeoXtru *shGroundFull = new TGeoXtru(2);
	shGroundFull->SetName(Form("SH_GFOIL_%s_FULL", type));
	shGroundFull->DefinePolygon(14, x, y);
	shGroundFull->DefineSection(0, -0.5*thickness, 0., 0., 1.0);
	shGroundFull->DefineSection(1,  0.5*thickness, 0., 0., 1.0);
	
	// this volume contains some holes which are here implemented as simple boxes
	// of fixed size, which are displaced along the shape itself and then composed
	// using the facilities of the TGeo package
	
	Double_t holeLength = fgkmm * 10.00;
	Double_t holeWidth  = fgkmm *  7.50;
	Double_t holeSepX0  = fgkmm *  7.05;  // separation between center of first hole and left border
	Double_t holeSepXC  = fgkmm * 14.00;  // separation between the centers of two consecutive holes
	Double_t holeSepX1  = fgkmm * 15.42;  // separation between centers of 5th and 6th hole
	Double_t holeSepX2  = fgkmm * 22.00;  // separation between centers of 10th and 11th hole
	if (!kap) {
		holeSepX0  -= fgkmm * 0.2;
		holeLength += fgkmm * 0.4;
		holeWidth  += fgkmm * 0.4;
	}
	
	// X position of hole center (will change for each hole)
	Double_t holeX = -0.5*length;
	// Y position of center of all holes (= 4.4 mm from upper border)
	Double_t holeY = 0.5*(width - holeWidth) - widthMin;
	if (!kap) holeY += 0.04;
		
	// create a shape for the holes (common)
	TGeoBBox *shHole = new TGeoBBox(Form("%sGFOIL_HOLE", type), 0.5*holeLength, 0.5*holeWidth, 0.5*thickness + 0.01);
	
	// insert the holes in the XTRU shape:
	// starting from the first value of X, they are simply shifted along this axis
	char name[200];
	TGeoTranslation *transHole[11];
	TString strComposite(Form("SH_GFOIL_%s_FULL - (", type));
	for (Int_t i = 0; i < 11; i++) {
		// set the position of the hole, depending on index
		if (i == 0) {
			holeX += holeSepX0;
		}
		else if (i < 4) {
			holeX += holeSepXC;
		}
		else if (i == 4) {
			holeX += holeSepX1;
		}
		else if (i < 10) {
			holeX += holeSepXC;
		}
		else {
			holeX += holeSepX2;
		}
		cout << i << " --> X = " << holeX << endl;
		sprintf(name, "TR_GFOIL_%s_HOLE%d", type, i);
		transHole[i] = new TGeoTranslation(name, holeX, holeY, 0.0);
		transHole[i]->RegisterYourself();
		strComposite.Append(Form("%sGFOIL_HOLE:%s", type, name));
		if (i < 10) strComposite.Append("+"); else strComposite.Append(")");
	}
	
	// create composite shape (with holes)
	TGeoCompositeShape *shGround = new TGeoCompositeShape(Form("SH_GFOIL_%s", type), strComposite.Data());
	
	// create the volume
	TGeoVolume *vol = new TGeoVolume("VOL", shGround, vacuum);
	
	// close and draw
	mgr->SetTopVolume(vol);
	mgr->CloseGeometry();
	mgr->CheckOverlaps(0.001);
	mgr->SetVisLevel(0);
	vol->Draw("ogl");
}